The object of the present invention is a pharmaceutical preparation for oral use, especially a tablet, which as its active ingredient contains a pharmacologically acceptable salt of dichloromethylene bisphoshonic acid, i.e. a clodronate, especially disodium clodronate.
Dichloromethylene bisphosphonic acid, especially in the form of its salt, such as the disodium salt, is a known drug for example for the treatment of diseases relating to the calcium metabolism and to the sceletal system, such as to the metabolism of the bone, for example for osteoporosis.
Clodronate has previously been administered orally in the form of conventional compressed tablets or capsules. Such a tablet or capsule disintegrates in the stomach of the patient releasing the active agent, which in the acidic environment of the stomach is converted to the free acid form. As clodronic acid is poorly absorbed, the bioavailability of the active agent will be low, and consequently the required dosage level has to be increased. This in turn is a disadvantage as a large tablet has to be used, which is inconvenient for the patient and reduces patient compliance. Also a large dose increases the risk for side-effects.